MMSC 491 Exam 1 QUESTIONS WITH |\ |\ |\ |\ |\ |\
ANSWERS
With reference to aberrant methylation of bases which of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
following statements, if any, is false? |\ |\ |\ |\ |\
A. S-adenosylmethionine donates methyl groups to a range of
|\ |\ |\ |\ |\ |\ |\ |\ |\
different molecules in cells and frequently inappropriately
|\ |\ |\ |\ |\ |\ |\
methylates bases in DNA. |\ |\ |\
B. Guanine is occasionally methylated to give O-6-methylguanine
|\ |\ |\ |\ |\ |\ |\
which base pairs with adenine rather than with cytidine.
|\ |\ |\ |\ |\ |\ |\ |\ |\
C. In each nucleated cell, about 300-600 adenines are converted
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
to 3-methyladenine per day.
|\ |\ |\
D. 3-methyladenine can be a cytotoxic base: it distorts the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
double helix and that can disrupt crucial DNA-protein
|\ |\ |\ |\ |\ |\ |\ |\
interactions. - CORRECT ANSWERS ✔✔B |\ |\ |\ |\
With reference to base cross-linking, which, if any, of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
following statements, is false? |\ |\ |\
A. Base cross-linking means that covalent bonds form between
|\ |\ |\ |\ |\ |\ |\ |\ |\
two bases.|\
B. The cross-linked bases are on opposing DNA strands.
|\ |\ |\ |\ |\ |\ |\ |\
C. The anti-cancer agent cisplatin causes a type of cross-linking
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
between two guanine residues. |\ |\ |\
D. Pyrimidine dimers are a type of base cross-linking that is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
commonly induced by excess exposure to sunlight. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔B |\
,Which, if any, of the following statements is false, regarding the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sources of genetic variation? |\ |\ |\
A. Most of the inherited changes in our DNA arise because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
exposure to extracellular mutagens, including radiation sources
|\ |\ |\ |\ |\ |\ |\
and chemical mutagens.
|\ |\
B. Most of the inherited changes in our DNA arise because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
unavoidable endogenous errors in cellular mechanisms and |\ |\ |\ |\ |\ |\ |\
harmful effects of certain natural molecules and atoms within our
|\ |\ |\ |\ |\ |\ |\ |\ |\
cells.
|\
C. Errors in DNA replication and DNA repair are a major source of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
mutations in our cells. |\ |\ |\
D. Significant chemical damage is sustained by DNA because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
its proximity to water molecules in our cells. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔A |\
Nucleic acid hybridization assays are normally carried out under
|\ |\ |\ |\ |\ |\ |\ |\ |\
relaxed hybridization stringency (to maximize the chances of
|\ |\ |\ |\ |\ |\ |\ |\
heteroduplex formation) but afterwards, washes are carried out |\ |\ |\ |\ |\ |\ |\ |\
that can be designed to favor perfectly matched sequences only
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
by changing some parameter. Which, if any, of the following
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
changes would be consistent with that aim?
|\ |\ |\ |\ |\ |\
a) An increase in temperature.
|\ |\ |\ |\
b) An increase in salt concentration.
|\ |\ |\ |\ |\
c) An increase in the concentration of a polar molecule, such as
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
urea or formamide. |\ |\
, d) Both A and C
|\ |\ |\ |\
E) A, B, and C - CORRECT ANSWERS ✔✔D
|\ |\ |\ |\ |\ |\ |\ |\
Which of the following statements, if any, is false?
|\ |\ |\ |\ |\ |\ |\ |\
A. PCR requires the use of a heat-stable DNA polymerase to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
make copies of the template DNA.
|\ |\ |\ |\ |\
B. PCR is usually used to amplify a specific DNA sequence of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
interest using |\
C. Oligonucleotide primers that bind to closely flanking
|\ |\ |\ |\ |\ |\ |\ |\
sequences.
D. PCR is superior to cell-based DNA cloning for two major
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
reasons: it is much quicker and it allows much greater DNA
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
amplification. - CORRECT ANSWERS ✔✔D |\ |\ |\ |\
For many of our genes, the initial RNA transcript needs to be
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
cleaved into pieces. Some of the pieces, called ____ ____, are
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
discarded, but other alternating pieces called ___ ____ are
|\ |\ |\ |\ |\ |\ |\ |\ |\
retained and fused in the same linear order as their order when
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
transcribed. - CORRECT ANSWERS ✔✔introns, exons |\ |\ |\ |\ |\
Which, if any, of the following statements are false?
|\ |\ |\ |\ |\ |\ |\ |\
a) Constitutive heterochromatin remains highly condensed
|\ |\ |\ |\ |\ |\
throughout the cell cycle. |\ |\ |\
ANSWERS
With reference to aberrant methylation of bases which of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
following statements, if any, is false? |\ |\ |\ |\ |\
A. S-adenosylmethionine donates methyl groups to a range of
|\ |\ |\ |\ |\ |\ |\ |\ |\
different molecules in cells and frequently inappropriately
|\ |\ |\ |\ |\ |\ |\
methylates bases in DNA. |\ |\ |\
B. Guanine is occasionally methylated to give O-6-methylguanine
|\ |\ |\ |\ |\ |\ |\
which base pairs with adenine rather than with cytidine.
|\ |\ |\ |\ |\ |\ |\ |\ |\
C. In each nucleated cell, about 300-600 adenines are converted
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
to 3-methyladenine per day.
|\ |\ |\
D. 3-methyladenine can be a cytotoxic base: it distorts the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
double helix and that can disrupt crucial DNA-protein
|\ |\ |\ |\ |\ |\ |\ |\
interactions. - CORRECT ANSWERS ✔✔B |\ |\ |\ |\
With reference to base cross-linking, which, if any, of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
following statements, is false? |\ |\ |\
A. Base cross-linking means that covalent bonds form between
|\ |\ |\ |\ |\ |\ |\ |\ |\
two bases.|\
B. The cross-linked bases are on opposing DNA strands.
|\ |\ |\ |\ |\ |\ |\ |\
C. The anti-cancer agent cisplatin causes a type of cross-linking
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
between two guanine residues. |\ |\ |\
D. Pyrimidine dimers are a type of base cross-linking that is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
commonly induced by excess exposure to sunlight. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔B |\
,Which, if any, of the following statements is false, regarding the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sources of genetic variation? |\ |\ |\
A. Most of the inherited changes in our DNA arise because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
exposure to extracellular mutagens, including radiation sources
|\ |\ |\ |\ |\ |\ |\
and chemical mutagens.
|\ |\
B. Most of the inherited changes in our DNA arise because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
unavoidable endogenous errors in cellular mechanisms and |\ |\ |\ |\ |\ |\ |\
harmful effects of certain natural molecules and atoms within our
|\ |\ |\ |\ |\ |\ |\ |\ |\
cells.
|\
C. Errors in DNA replication and DNA repair are a major source of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
mutations in our cells. |\ |\ |\
D. Significant chemical damage is sustained by DNA because of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
its proximity to water molecules in our cells. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔A |\
Nucleic acid hybridization assays are normally carried out under
|\ |\ |\ |\ |\ |\ |\ |\ |\
relaxed hybridization stringency (to maximize the chances of
|\ |\ |\ |\ |\ |\ |\ |\
heteroduplex formation) but afterwards, washes are carried out |\ |\ |\ |\ |\ |\ |\ |\
that can be designed to favor perfectly matched sequences only
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
by changing some parameter. Which, if any, of the following
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
changes would be consistent with that aim?
|\ |\ |\ |\ |\ |\
a) An increase in temperature.
|\ |\ |\ |\
b) An increase in salt concentration.
|\ |\ |\ |\ |\
c) An increase in the concentration of a polar molecule, such as
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
urea or formamide. |\ |\
, d) Both A and C
|\ |\ |\ |\
E) A, B, and C - CORRECT ANSWERS ✔✔D
|\ |\ |\ |\ |\ |\ |\ |\
Which of the following statements, if any, is false?
|\ |\ |\ |\ |\ |\ |\ |\
A. PCR requires the use of a heat-stable DNA polymerase to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
make copies of the template DNA.
|\ |\ |\ |\ |\
B. PCR is usually used to amplify a specific DNA sequence of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
interest using |\
C. Oligonucleotide primers that bind to closely flanking
|\ |\ |\ |\ |\ |\ |\ |\
sequences.
D. PCR is superior to cell-based DNA cloning for two major
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
reasons: it is much quicker and it allows much greater DNA
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
amplification. - CORRECT ANSWERS ✔✔D |\ |\ |\ |\
For many of our genes, the initial RNA transcript needs to be
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
cleaved into pieces. Some of the pieces, called ____ ____, are
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
discarded, but other alternating pieces called ___ ____ are
|\ |\ |\ |\ |\ |\ |\ |\ |\
retained and fused in the same linear order as their order when
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
transcribed. - CORRECT ANSWERS ✔✔introns, exons |\ |\ |\ |\ |\
Which, if any, of the following statements are false?
|\ |\ |\ |\ |\ |\ |\ |\
a) Constitutive heterochromatin remains highly condensed
|\ |\ |\ |\ |\ |\
throughout the cell cycle. |\ |\ |\
